Thomas County cat. [volume] (Colby, Kan.) 1885-1891, 1887-06-09

money with her other house furnish
ings. Philadelphia Record.
CELESTIAL PHOTOGRAPHY.
Achievements Made Possible by the Re-
cent Progress OF the Art
Although celestial photography is
upward of half century old. the moon
having been photographed by DR.. J.
w. Draper in 1910. yet within the past
two or three years it has become al
most new art It's progress has been
so rapid that it has the effect of fresh
discovery. There is now no longer any
doubt that the hopes of astronomers in
this direction can be realized, and that
the Photographic camera can be made
to take the place, and in some respects
more than take the place, of the eye in
telescope work. Excellent photo
graphs are now obtained not only Of
the sun, the moon. the brighter stars,
comets and nebule, but also of the
spectra of many heavenly bodies, and
of phenomena. such as faint stars and
invisible nebule, which the eye can not
detect at all. even when aided by the
most powerful telescope. A notable
discovery of this kind has been made
in the familiar group Of stars called the
Pleiades. Apparently connected with
one of these stars, which has been
| known for ages under the name of
Maia, is strange nebulous mass.
which is clearly seen in photographs
of the Pleiades, taken in the past two
years. though no telescope shows any
trace of it to the eye. Photographs of
the heavens also show stars whose ex-
istence would have been unknown to
us but for the marvellous power of the
Photographic plate to catch and hold
the image of objects too obscure to
sensibly affect the human retina.
There are two ways in which the
camera has an advantage over the eye.
First, it can accumulate impressions
that is to say. it is able by continued
exposure to obtain an image of an OBJ
ject which may be 80 faint that a
shorter exposure would give no image.
This, of course. is power that the eye
does not possess. 1t is equivalent to
being able to see plainly by long gaz-
ing what can not be seen at all by
brief inspection. Then the photo
graphic plate is sensitive to the So
called actinic rays. VIII ch do not pro-
duce the impression Of light and con-
sequently do not affe9 the eye. Thus
photography furnishes astronomy with
an improved eye. capable of ranging
nobody yet knows how far into the
ADVISES of the universe.
The recent progress Of celestial
photography has been so great that it
has created a new branch of observa-
tional astronomy, and. as in the use OF
the spectroscope, it has been found that
specialists are needed to fully develop
it. Achievements in the way OF
measuring. sounding and mapping the
visible universe, which astronomers a
generation ago would hardly have
dared to dream of, are now clearly
within the range of possible accom-
plishment 1t is regarded as en-
tirely practicable to obtain within
the short space of ten years
a series of photographs including the
whole heavens. and containing millions
upon millions of stars that can not be
seen with the naked eye. The value OF
such photographs to future astron-
omers would be inestimablc. Showing
the true places of so many stars at the
date when the photographs were made,
they would render 1t easy to detect any
changes of place among the stars.
Such changes are known to occur from
various causes in all quarters of the
heavens. but the difficulty has been to
measure them. BY the Photographic
method. star motions can be studied
with high degree of accuracy; and
through such study astronomers can
arrive at a far more complete knowl-
edge than they now possess of the form
and structure Of the universe of suns,
in which our own sun shines only as
luminary Of minor rank--N 7.
Sun.